The price of sustainability of a traditional irrigation system in Northern Thailand

In recent years in northern Thailand, the traditional surface-water irrigation system known as muang fai has been challenged by the introduction of small-scale, groundwater pumping technology. This trend presents concerns about the sustainability of the system, as the new technology uses more water but produces lower-quality agricultural outputs. In this paper, we provide evidence that farmers who use relatively modern irrigation technology (ground water pumping systems) are willing to switch to a more traditional (hundreds of years old) and more sustainable surface water irrigation system. In the Sop Rong region in northern Thailand, we surveyed 570 longan farmers, approximately half being muang fai members and half using pumped groundwater. We designed an experiment for the second group to check whether they were interested in becoming muang fai members in a scenario where they have access to the canal system. We found that almost half of them were willing to pay fees to become members and that the negative relationship between membership fees and the willingness to join is robust after controlling for all other relevant factors. Despite this positive result for sustainability, suggesting that there is a price at which many farmers would be willing to switch to a more water-saving system, few farmers are making the shift. We conclude that there are strong social pressures that discourage them from doing so. Such social influences are probably an important and often overlooked determinant of efforts to achieve sustainability.